Liner for centrifugal casting molds



Nov. 29, 1949 E. R. OLSEN ET LI NER FOR CENTRIFUGAL CASTING MOLDS Filed Aug. 28, 1946 INVENTORJ Ewes! R Olden Rudo/p/z fT'F/ora AT mvzz Patented Nov. 29, 1949 Ernest B. Olsen. Rudolph I. Flora, and Cliflord J. Lonnee, Mulkegon, Mich, aaslgnors to Hastings Manufacturing Company, Hastings, vMich.

Application August 28, 1946, Serial No. 693,518

This invention relates to improvements in liner for centrifugal casting molds.

The principal objects of this invention are: I

First, to provide a liner for a permanent mold casting device which will present a smooth, even surface to the molten metal and at the same time permit the escape along the walls of the liner of gases formed in the casting operation.

Second, to provide a preformed heat resistant liner for a permanent mold which will form pockets between the liner and the mold for the escape of gases, but which will be adequately supported to form an even casting surface.

Third to provide a heat resistant liner for a permanent mold which is easily and. inexpensively formed from sheet material.

' Fourth, to provide an improved mold or mold apparatus which facilitates the making of castings.

Other objects relating to details and economies of the inventionwill appear from the description to follow. The invention is defined and pointed out in the claims.

The drawings, of which there is one sheet, illustrate a casting device employing our liner and two modified forms of liners.

Fig. 1 is a plan view partially broken away and in cross-section illustrating a centrifugal molding device embodying our invention.

liner illustrated in Fig. 5.

The reference character I indicates generally a centrifugal casting machine which is provided with a permanent tubular mold 2 which is mount- .1 and annular flange 8 connect the end plate 3 and sleeve 4 with the jacket in spaced radial relationship with the mold 2 so that air may be circulated around the mold by being pumped in 4 Claims. (Cl- 22-1135) 2 the hollow shaft In for cooling the mold. The construction and operation ofthe mold is more particularly described and claimed in our copending application, Serial No. 691,348, filed August 17, 1946.

Positioned within the sleeve 5 is the preformed bendable sheet mold liner II which is formed of sheet asbestos material and bent or rolled into tubular shape when it is installed in the mold to fit snugly within the sleeve 5. As is shown in Figs. 2 .and 3, the outer surface of the liner, H is relatively rough or unfinished, leaving a series of small irregular interconnected passages or channels l2. The surface may be formed by sinface cooking, rolling. pillaring, or stipling. The inner surface of the liner H is as smooth as is practical and presents a regular and accurate surface against which the molten metal will be cast.

Gases formed in the mold due to burning of the starch or binder, moisture in the liner or otherwise generated or produced during'the casting operation, emerge into the small passages or depressions l2 and follow through this space to the nearest radial hole 8 in the sleeve 5 from where they may escape without causing the liner to bulge inwardly; out of shape, and spoil the shape of the casting.

The individual sheets areas long as the permanent mold they are to be used invand slightlylessin width than the circumference of the mold, so that a narrow split is left in the liner as shown in Fig. 2 when installed in the mold. The modified form of liner illustrated in Fig. c consists of an inner ply l3 which is joined with an outercorrugated ply M in a laminated constructionij The grooves of the corrugated sheet run longitudinally so as not to interfere with the rolling of the liner into tubular form. Liners made from sheets of this multi-ply material permit the escape of casting gases along the fines or passages formed by the corrugations of the outer ply I4 and the wall of the mold, while at the same time adequately supporting the smooth inner ply l3 to form the casting surface.

The modified form of liner shown in Figs. 5 and 6 is also of laminated construction and consists of an inner ply l5 and an outer ply l6 which has been rolled or pressed into the regular series of rectangular depressions II separated by the ribs l8. The lower surfaces of the depression l6 support the inner ply I5 while casting gases may escape along the ribs I8.

through the central pipe 9 and exhausted through All three modifications of the liner are manuamazes factured in preformed bendable sheet form and are rolled to permit insertion in the mold cavity and readily expand into supported relation to the wall thereof. While asbestos has been described as a highly desirable material for the sheets, any heat resistant material which will not be consumed by the molten metal may be used.

As is explained more fully in the above mentioned copending application, the asbestos liner aids in controlling the grain structure of the casting by retarding the cooling rate at its surface and makes it easier to withdraw the casting from the mold as the liner is removed from the mold with the casting as a unit. The liner also protects and prolongs the life of the permanent mold.

We have illustrated and described our invention in highly practical embodiments thereof and with certain modifications or adaptations. We

have not illustrated or described other modiflca-.

tions or adaptations which we contemplate as it is believed that this disclosure will enable those skilled in the art to embody or adapt our invention as may be desired.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is:

1. A mold comprising a tubular mold member of metal, and a bendable resilient liner of preformed sheet asbestos for the mold cavity wall thereof loosely arranged in rolled position therein and radially supported against unrolling by the wall thereof with the edges of the sheet in closely adjacent non-attached relation. the liner being unconnected with the mold wall and being removable therefrom with the casting formed therein, the liner having a substantially smooth inner surface and a corrugated outer surface in supported engagement with the mold wall and meeting therewith to provide vent openings between the liner and the mold wall.

2. A tubular metal mold member having an approximately cylindrical mold cavity wall of uniform cross section from end to end, and a bendable resilient liner of preformed sheet asbestos disposed in rolled position within the mold cavity in radially supported relation to the wall thereof and constituting a substantially complete facing therefor, the liner being free to expand radially by unrolling into close supported contact with the mold wall but being otherwise entirely unconnected to the mold wall, the liner sheet having a substantially smooth inner surface and a' roughened outer surface coacting with the mold wall to provide venting spaces between the liner and the wall.

3. A mold comprising a rotatably mounted tubular mold member, and a bendable resilient liner of preformed sheet heat resistant material for the mold cavity wall thereof loosely arranged in rolled position therein and radially supported the mold wall and being removable therefrom' with the casting formed therein, the liner having a multiplicity of spaced raised elements on its outer surface in supported engagement with the mold wall and coacting therewith to provide vent openings between the liner and the mold wall.

4. A tubular metal mold member having an approximately cylindrical mold cavity wall of uniform cross section from end to end, and a bendable resilient liner of preformed sheet asbestos disposed in rolled position within the mold cavity in radially supported relation to the wall thereof and constituting a substantially complete facing therefor, the liner being free to expand radially by unrolling into close supported contact with the mold wall but being otherwise entirely unconnected to the mold wall, the liner sheet having closely spaced supporting protuberances on the outersurface coacting with the mold wall to provide venting spaces between the liner and the wall. I

ERNEST R. OLSEN. RUDOLPH F. FLORA. CLIFFORD J. IONNEE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 359,483 Whitley Mar. 15, 1887 652,756 Deming July 3, 1900 661,143 Grasser Nov. 6. 1900 665,865 Baker Jan. 15, 1901 686,952 Price et al Nov. 19, 1901 1,249,101 Jacobs Dec. 4, 1917 1,743,932 Reed Jan. 14, 1930 1,815,608 Birdsall July 21, 1931 2,040,348 Victor et al May 12, 1936 2,239,530 Langenohl et al. Apr. 22, 1941 

